Best Position for a Service Centre LeetCode solution in JavaScript

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/**
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 * @param {number[][]} positions
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 * @return {number}
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 */
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var getMinDistSum = function (positions) {
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  /**
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      identify the vertical range and horizontal range
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      start from the center of positions
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      calc the distance
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        test the 4 direction with a certain step
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            if any distance is closer, choose it as the new candidate
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        if all 4 are further, reduce the step
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    **/
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  let xSum = 0;
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  let ySum = 0;
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  for (const [x, y] of positions) {
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    xSum += x;
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    ySum += y;
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  }
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  let n = positions.length;
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  let x = xSum / n;
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  let y = ySum / n;
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  let step = 0.5;
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  const dirs = [
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    [0, 1],
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    [0, -1],
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    [-1, 0],
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    [1, 0],
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  ];
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  while (step >= 10 ** -5) {
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    const dist = calcDist(x, y);
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    let found = false;
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    for (const [xDiff, yDiff] of dirs) {
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      const newX = x + xDiff * step;
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      const newY = y + yDiff * step;
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      const newDist = calcDist(newX, newY);
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      // console.log(x, y, newDist, dist);
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      if (newDist < dist) {
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        x = newX;
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        y = newY;
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        found = true;
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        break;
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      }
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    }
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    if (!found) {
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      step /= 2;
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    }
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  }
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  return calcDist(x, y);
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  function calcDist(x, y) {
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    let dist = 0;
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    for (const [posX, posY] of positions) {
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      dist += Math.sqrt((x - posX) ** 2 + (y - posY) ** 2);
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    }
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    return dist;
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  }
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};